Many industrial machines are provided therein with various mechanical elements, such as gears and bearings. Lubricant, such as oil or grease, is supplied to these mechanical elements in order to smoothen motions and improve durability of the mechanical elements.
As one system which supplies lubricant, for example, in FIG. 3 of Patent Document 1, a lubricant supplying apparatus for supplying lubricant to external devices is disclosed. The lubricant supplying apparatus includes a lubricant tank where lubricant is stored, a pump device attached to an opening of the lubricant tank, a control device which sends an operative instruction to the pump device, and a tube extending from the lubricant tank. In the lubricant supplying apparatus, a quantity of lubricant to be supplied is inputted into the control device, and the pump device which is actuated in accordance with the operative instruction sent from the control device sends the set quantity of lubricant to the tube from the lubricant tank, and lubricant is discharged from a discharge part at a tip end of the tube.